Joydrive and Self Tests
DIGIN and DIGOUT Test
A subsequent self-test lets you examine the values of the eight digital input (ID0
–
7) and
output (OD0-7) ports associated with User I/O on your ActivMedia robot’s microcontroller.
The state of each port is mapped into a series of eight digits displayed on the LCD. Each
digit, 0 or 1, representing the
ON
or
OFF
state of a port, numbered right-to-left from 0 to 7.
For instance, in the example below, digital input (
DIGIN
) ports 1 and 5 are
ON
; the rest are
OFF
:
DIGIN: 00100010
DIGOUT: 01010101
The
DIGOUT
ports automatically and rhythmically toggle
ON
and
OFF
.
The basic microcontroller has no attachments to the I/O ports. Because their normal
state is floating, the
DIGIN
readings will vary. The
DIGIN
self-test becomes useful, of
course, when you have equipment attached to one or more of the digital input ports.
See Appendix A for the location of the digital input and output ports.
ANALOG Tests
P2OS versions 1.2 and later let you alternatively use four of the digital input ports as
analog-to-digital (A/D) input ports. And there is one dedicated A/D port on the User I/O
connector. The ANALOG self-test measures the voltage (0-5 VDC) applied to each of
the A/D ports and display its digitized value as a single byte in hexadecimal on the LCD:
ANALOG #1: A9
13.2*
Press the white MOTORS button to select the next analog port, 2-5. Port #5 is the
dedicated and default A/D port. Like
DIGIN
, the measured value is unreliable unless you
connect something to the port.
See Appendix A for the location of the A/D ports on the microcontroller.
User PWMs
P2OS versions 1.2 and later let you alternatively use four of the digital output ports as
pulse-width-modulating sources to drive servo motors, for example. The User PWM self-
test puts a one millisecond pulse onto each of these four PWM ports. Monitor them with
an oscilloscope.
See Appendix A for the location of the PWM ports on the microcontroller.
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